TLE7258D_15 Datasheet, PDF (15/31 Pages) Infineon Technologies AG – TLE7258D

4.8
Undervoltage Detection
TLE7258D
Functional Description
Undervoltage
V_S
detection level V_S,UV,OFF
Undervoltage hysteresis V_S,UV,HYS
Supply voltage V_S
Undervoltage release level V_S,UV,ON
Power-on reset level V_S,UV,PON
Blanking time t_blank,UV
t
Normal Operation mode
Communication blocked
Normal Operation mode
TLE7258_UNDERVOLTAGE_EARLY
Figure 11 Early undervoltage detection
The TLE7258D has undervoltage detection on the V_S supply pin with two different thresholds:
• In Normal Operation mode the TLE7258D blocks the communication between the LIN bus and the
microcontroller when detecting undervoltage events. However, no mode change will occur. After V_S rises
above the undervoltage release level V_S,UV,REL, the bus communication interface will be released when the
signal on the TxD input goes “high”. See Figure 11.
• In case the power supply V_S drops down below the power-on reset level V_S,UV,PON the TLE7258D not only
blocks the communication between the LIN bus and the microcontroller, it also changes the operation mode
to Standby mode after V_S supply recovery. In Standby mode the TLE7258D indicates a power-up event on the
RxD output. The power-on reset level is active in all operation modes.See Figure 12.
Undervoltage
V_S
detection level V_S,UV,OFF
Undervoltage hysteresis V_S,UV,HYS
Normal Operation mode
Device unpowered
Communication blocked
Figure 12 Undervoltage detection and power-on reset
Supply voltage V_S
Undervoltage release level V_S,UV,ON
Power-on reset level V_S,UV,PON
Blanking time t_blank,UV
t
Standby mode (EN = „low“)
Normal Operation mode (EN = “high“)
TLE7258_UNDERVOLTAGE_RESET
4.9
3.3 V and 5 V Logic Capability
The TLE7258D can be used for 3.3 V and 5 V microcontrollers. The logic inputs and the outputs are capable to
operate with both voltage levels. The RxD output needs an external pull-up resistor to the microcontroller supply
to define the voltage level (see Chapter 7.6 “RxD Pull-up Resistor” on Page 26 and Figure 15).
Data Sheet
15
Rev. 1.2, 2014-12-08